# Annihilation of low energy antiprotons in silicon

Abstract : The goal of the AE$\mathrm{\bar{g}}$IS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter. To achieve this goal, the AE$\mathrm{\bar{g}}$IS collaboration will produce a pulsed, cold (100 mK) antihydrogen beam with a velocity of a few 100 m/s and measure the magnitude of the vertical deflection of the beam from a straight path. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1$%$ precision on the measurement of $\bar{g}$ with about 600 reconstructed and time tagged annihilations. We present here, to the best of our knowledge, the first direct measurement of antiproton annihilation in a segmented silicon sensor, the first step towards designing a position sensitive silicon detector for the AE$\mathrm{\bar{g}}$IS experiment. We also present a first comparison with Monte Carlo simulations (GEANT4) for antiproton energies below 5 MeV
Document type :
Preprints, Working Papers, ...

http://hal.in2p3.fr/in2p3-00999409
Contributor : Sylvie Flores <>
Submitted on : Tuesday, June 3, 2014 - 3:19:19 PM
Last modification on : Friday, September 10, 2021 - 1:50:13 PM

### Identifiers

• HAL Id : in2p3-00999409, version 1
• ARXIV : 1311.4982

### Citation

S. Aghion, O. Ahlén, A. S. Belov, G. Bonomi, P. Bräunig, et al.. Annihilation of low energy antiprotons in silicon. 2014. ⟨in2p3-00999409⟩

Record views